1.Field of the Invention
The present invention relates to a garbage disposing device for decomposing organic wastes such as food wastes by a microorganism, and particularly the garbage disposing device capable of efficiently performing the decomposing treatment with reduced energy without using a large-scale deodorizer for deodorizing an air containing unpleasant odor caused by the decomposition.
2. Disclosure of the Prior Art
In the past, devices for decomposing organic wastes containing water such as food wastes by a microorganism have been known. In the devices, a gas generated by the decomposition of the food wastes is exhausted from a treatment chamber. When a water vapor amount in the exhaust gas exceeds a saturated water vapor amount, dewdrops occur. To efficiently perform the decomposing treatment, a large-scale exhausting unit having a high exhausting capability is needed. In addition, since unpleasant odor is generated during the decomposing treatment, it is necessary to use a deodorizer for removing the unpleasant odor.
However, to remove a large amount of the unpleasant odor contained in the exhaust gas supplied from the large-scale exhausting unit, a purifying device having a high purifying capability will be required. For example, when an adsorbent is used for the purifying device, there is a problem that the adsorbent must be exchanged or regenerated frequently. On the other hand, when a microorganism deodorizer or the like is used for the purifying device, a large deodorizing vessel would be needed. As a result, there is a problem that the garbage disposing device is large-scaled as a whole. In addition, when a catalyst is used for the purifying device, it is not necessary to frequently exchange the adsorbent. However, the disposing device is large-scaled as a whole, so that a large amount of energy is consumed to heat the air. Additionally, energy is required to exhaust the air. Therefore, it is desired to develop a garbage disposing system capable of performing the deodorizing treatment with reduced energy without lowering the decomposition efficiency of the food wastes by the microorganism.
For example, FIG. 16 shows a schematic diagram of a garbage disposing device disclosed in Japanese Patent Early Publication [KOKAI] No. 8-253384. This device 1F comprises a treatment chamber 10F in which food wastes 2F are decomposed by a microorganism, a heater 80F disposed at a bottom of the treatment chamber, exhaust passage 21F extending from the treatment chamber to exhaust an air containing unpleasant odor generated by the decomposition of the food wastes, a return path 22F diverged from the exhaust passage at a diverging portion 23F to connect with the treatment chamber 10F, dehumidifier 30F disposed in the return path to dehumidify an air supplied to the return path, intake passage 20F formed at upstream of the dehumidifier in the return path to take in a fresh air from the outside, fan 13F disposed at downstream of the dehumidifier, humidity sensor 62F disposed in the treatment chamber, and a control unit 3F for controlling the dehumidifier and the fan.
The air in the treatment chamber 10F is sent to the return path 22F by operating the fan 13F, and returned again to the treatment chamber after water contained in the air is removed by the dehumidifier 30F. When humidity measured by the humidity sensor 62F is high, the control unit 3F controls the fan 13F and the dehumidifier 30F to increase the dehumidifying capability. Thus, a suitable environment for the decomposing treatment of the food wastes by the microorganism can be maintained in the treatment chamber.
However, in this disposing device 1F, a sufficient countermeasure is not taken against the unpleasant odor of the air exhausted through the exhaust passage 21F to the outside. In addition, since the water vapor in the air sent to the return path 22F is removed by generating dewdrops in the dehumidifier 30F, the removed dewdrops are drained through a drainpipe 33F. In this case, there is a possibility that a water-soluble unpleasant odor component dissolves in the dewdrops, so that the removed dewdrops emit strong unpleasant odor. This will give a bad influence to the environments around the disposing device.
Thus, there is room for further improvement in the prior art system for decomposing the organic wastes such as food wastes by the microorganism.
For improving the above problems, an object of the present invention is to provide a garbage disposing device which is capable of removing unpleasant odor in a gas generated by a decomposition of food wastes by a microorganism, and efficiently decomposing the food wastes with reduced energy. That is, the garbage disposing device of the present invention includes a treatment chamber used to decompose the food wastes by the microorganism, an intake passage for supplying a fresh air into the treatment chamber from an outside, and an exhaust passage connected to an outlet of the treatment chamber at one end and having an exhaust port at the other end. A dehumidifier is provided in the exhaust passage. The dehumidifier includes a dehumidifying agent and a regenerating unit for removing water adsorbed on the dehumidifying agent to regenerate the dehumidifying agent. A return path extends from a diverging portion in the exhaust passage, which is positioned at downstream of the dehumidifier, to the treatment chamber. A ventilator is provided at upstream of the diverging portion to send the air containing the unpleasant odor generated in the treatment chamber toward the outside through the exhaust passage. A deodorizer for removing the unpleasant odor from the air to be exhausted through the exhaust port is provided between the dehumidifier and the exhaust port in the exhaust passage. An exhaust airflow adjuster is provided at the diverging portion to adjust an air amount to be returned from the exhaust passage to the treatment chamber through the return path. A control unit controls the exhaust airflow adjuster according to the following manner. When the garbage disposing device is in an ordinary use mode, the exhaust airflow adjuster is set to a first position where a part of an air supplied from the dehumidifier is exhausted through the exhaust port, and the remaining air is returned to the treatment chamber through the return path. When the garbage disposing device is in a regenerating operation mode for the dehumidifying agent, the exhaust airflow adjuster is set to a second position where the return path is closed at the diverging portion.
In the present invention, since a part of the gas exhausted from the treatment chamber is treated by the dehumidifier to remove water therefrom, and then returned to the treatment chamber through the return path so as to be used again for the decomposition of food wastes by the microorganism, it is possible to reduce an air amount exhausted to the outside through the exhaust passage. Therefore, a small deodorizer can be used in the present device. As a result, it is possible to small-size the garbage disposing device as a whole, and also save energy for operating the garbage disposing device.
It is a further object of the present invention is to provide a garbage disposing device characterized in that after the dehumidifying agent is heated to remove the adsorbed water therefrom, the dehumidifying agent can be rapidly cooled to enhance a recovery of the dehumidifier to the decomposing treatment of the food wastes. That is, after the regenerating operation for the dehumidifying agent is finished, the control unit sets the exhaust airflow adjuster to a third position where the exhaust passage is closed at the diverging portion. The dehumidifying agent can be efficiently cooled by a circulating air flowing in a closed path of the treatment chamberxe2x86x92the exhaust passagexe2x86x92the return pathxe2x86x92the treatment chamber. Since the exhaust passage extending toward the deodorizer is closed, it is possible to send a large amount of air in the closed path by increasing an output of the ventilator. As a result, the dehumidifying agent can be quickly cooled.
It is another object of the present invention is to provide a garbage disposing device characterized in that a heat exchanger not made of a corrosion resistance material is available, and waste heat collected from the exhaust gas flowing in the exhaust passage can be used to enhance the decomposition of the food wastes by the microorganism. That is, the heat exchanger is provided between the deodorizer and the exhaust port in the exhaust passage. A fresh air passing the intake passage can be warmed by the waste heat collected from the exhaust gas flowing in the exhaust passage by the heat exchanger. The warmed fresh air is introduced into the treatment chamber to enhance the decomposition of the food wastes. By the way, a corrosive gas containing a large amount of water vapor and ammonia is usually exhausted from the treatment chamber. Since the heat exchanger is provided at, downstream of the deodorizer, the heat exchanger is not exposed to the corrosive gas. Therefore, it is not necessary to use an expensive heat exchanger using the corrosion resistance material.
These and still other objects and advantages will become apparent from the following detail description of the preferred embodiments of the invention referring to the attached drawings.